Modelling urban growth for long-term planning under future climate uncertainty: A systematic review and decision pathway

Planning for high urban growth elevates the risks posed by climate uncertainty if planning policy is not linked to possible climate futures. Urban growth modelling (UGM) is often used to inform planning policy, but its ability to produce plausible long-term urban growth scenarios that can be integrated with global climate scenarios has not been adequately researched. Our aim was to systematically investigate the suitability of UGM for generating urban growth scenarios that are consistent with climate futures to assist long-term planning under future climate uncertainty. We reveal an array of UGM methods can deliver urban growth projections for a range of spatial scales that temporally align with climate futures. To help navigate this diversity, we propose a decision pathway that identifies appropriate choices at critical junctures in the modelling process, advancing a fit-for-purpose approach that better communicates the choices to users. We argue urban growth scenarios should reflect global climatic and socioeconomic scenarios to ensure consistent future narratives, which implies UGM must incorporate flexible future assumptions for climate-related variables and the socioeconomic drivers of land demand. Our decision pathway has the potential to be a valuable tool in promoting the use of UGM in assessing future climate risk, but its utility requires validation by urban planners making real-world decisions. We identified a gap between technical and practical innovation in UGM, which should be addressed if modelled urban growth scenarios are to assist long-term planning under future climate uncertainty, supporting sustainable and resilient urban futures. • Urban growth modelling can assist long-term planning under future climate uncertainty. • Urban growth scenarios should reflect global climatic and socioeconomic scenarios. • We propose a decision pathway for modelling that generates consistent urban futures. • Practical utility of the modelling pathway should be validated by urban planners.